import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class DBUtil {
    static String URL  = "jdbc:mysql://127.0.0.1:3306/database1?characterEncoding=utf8&useSSL=false";
    static String USERNAME = "root";
    static String PASSWORD = "root";

    static volatile DataSource dataSource = null;

    public static DataSource getDatasource(){
        if (dataSource == null){
            synchronized (DBUtil.class){
                if (dataSource == null){
                    dataSource = new MysqlDataSource();
                    ((MysqlDataSource) dataSource).setURL(URL);
                    ((MysqlDataSource) dataSource).setUser(USERNAME);
                    ((MysqlDataSource) dataSource).setPassword(PASSWORD);
                }
            }
        }
        return dataSource;
    }
    public static Connection getConnection() throws SQLException {
        return getDatasource().getConnection();
    }
    public static void close(Connection connection, PreparedStatement statement, ResultSet resultSet){
        if (connection != null){
            try {
                connection.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (statement != null){
            try {
                statement.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (resultSet != null){
            try {
                resultSet.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}
